NASA, Space Exploration, The USA and Russia...???

Factual Questions
41

That’s certainly true for some kinds of disasters, but not necessarily for others. A massive hit by a meteor could wipe the surface clean of life. A runaway greenhouse effect could make the Earth completely uninhabitable. A biological agent would be very hard to survive if it could live in host animals in the wild.

But I think that’s a moot point anyway, because I don’t think we can build a truly self-sustaining colony on Mars. At least, not in my lifetime or yours or Elon Musk’s, and perhaps not ever. As I said, we will have to discover some intrinsic reason for being there other than as an insurance policy against mankind’s destruction, because that kind of insurance is way too expensive and maybe even impossible.

Now, if people go there and find something of value to send back to Earth that more than pays for the support they would need from Earth, maybe a colony will start growing and one day in hundreds or thousands of years will get to the size where it’s self-sufficient. But because the costs are so much higher than going to the moon, I’d put my money on the Moon having something we can economically exploit, and even that is probably a long shot.

42

To be honest, I’m not concerned about radiation in the slightest. It’s not that it has no effect–but its effect is long term and with few if any acute problems at the low levels found in space. On planetoids, the problem is particularly innocuous due to planetary shielding and the fact that another half or so can be avoided by spending time underground. But even ignoring that, radiation will at most take a few years off a typical lifespan. Humans have survived and thrived in vastly more threatening environments.

Micro/hypogravity is probably the greater concern. I really wish the ISS (or some equivalent) had a low-G human centrifuge for long-term Martian and Moon gravity simulation. I would say that it’s completely unknown whether hypogravity environments are just as good as Earth, no better than microgravity, or somewhere in the middle. I don’t think there’s really good cause to even speculate one extreme or the other.

Nevertheless, bone density loss is not an obvious health concern until astronauts actually return to Earth. If they stay in space–does it matter? I don’t think we’ll really have an answer until we have true long-term space habitation (decades).

In short, we may not have to overcome these biological rigors (and as long as we’re comparing to The Expanse–they haven’t solved the bone density problem, either). Residents of space will be weak and die early, but they’ll live long enough to build a new civilization out there.

43

“Self sustaining” is an interesting concept. What does one need to be self-sustaining? Well, there’s the obvious stuff like food, water, and air. Those can be generated on Mars relatively easily.

But industrial stuff is backed by an enormous supply chain on Earth; one that could not possibly be replicated on Mars any time soon.

But 3D printing and similar technologies are moving the needle. For relatively low-precision parts, it is good enough, and getting better–one no longer needs a machine shop for a wide class of parts. The designs are also getting better–looking at “printable printers” (using fused plastic deposition), the ratios are getting much better over time. The very first ones were barely 10% printable parts by mass; more modern designs are 80-90%. Fastener-free designs, sliding parts instead of rolling, making use of complicated internal geometry, etc. are all things that have improved with experience.

The remainder is sometimes called the “vitamins”. It’s all the complex stuff like motors and semiconductors that can’t be 3D printed. Most likely, we’ll see 3D printed motors not too long from now (though maybe with vitamins of their own, like precision bearings).

Semiconductors of course are a long way off. Even if we started a small Martian colony now, I think it would be a century before there was a semiconductor fab on Mars. But maybe that’s ok–a cubic meter of semiconductor chips could supply a large settlement for a year. And they could be stored indefinitely. If one had a few tons stockpiled, one could perhaps hold out for a very long time in the face of losing shipments from Earth.

I think there is effectively a smoothly decaying curve, where the vitamins become a lower and lower percentage of the total due to improvements in manufacturing and the industrial base, and where at some level Mars (or the Moon) is still not totally self-sufficient, but enough that they can survive relatively minor disasters on Earth. And then at a lower level, major disasters, and then at some final low level they can hold out long enough to improve their own industrial base to become self-sufficient. This is centuries off, probably, but I think we’ll see some major improvements in the shortish term. At every level, there is going to be a strong drive for improved self-sufficiency since the costs for transport are so high.

44

How are those colonists supposed to live? To support high tech industry you need millions of people. Or, assuming we have quasi-magical advanced manufacturing, hundreds of thousands. Who is feeding them? Who is paying them? How are thry getting the staples of life? How are they able to have children and feed and clothe them?

You can’t subsidize it all from Earth. There has to be a local economy with enough productive activities that people can afford to buy goods from Earth. But that seems nearly impossible when shipping costs $10,000 per kg. Even if you make as much as you can locally and only outsource small, complex parts from Earth, it’s hard to imagine how it would be affordable. It’s also hard to imagine anything on Mars being valuable enough to warrant shipping to earth at such costs as well.

If Earth has to spend $1 million per year per person to sustain a martian colony, how can it possibly grow to a level where it is self-sustaining? That seems like a serious chicken and egg problem. And $1 million per year might only be 100 kg per person per year in import goods. I doubt if that’s even close to what they need, at least in the early days.

At least the moon may be useful for tourism, retirement, mining, and other activities. I’m not sure Mars has anything at all the Earth needs badly enough to warrant a mass presence there. Maybe the Moon doesn’t either, but it will be a hell of a lot cheaper to find out.

My personal belief is that the best we are going to do on Mars is an expensive McMurdo-type station with a few scientists or wealthy adventurers there. That will last until we run out of interesting things to do with such a station. I suspect living there is going to be harsh and difficult, and the people going there will want to come back to Earth after a stint and not live there permanently.

The Moon at least has a chance to fare better, simply because there is such a wide range of potential activities and because it is orders of magnitude easier to get to and from. But even that might not be enough to sustain any kind of large permanent presence there.

In both places, a colony cannot be artificially created. It has to arise out of necessity as we find useful things to do. It has to grow organically out of need because we value the things people do there.

But what happens if a company sends a probe to an asteroid, and finds a mountain of gold or platinum worth trillions of dollars? What if we find hundreds or thousands of such asteroids, and it kicks off a new gold rush? That’s the kind of thing that could trigger a massive push into space.

45

I read somewhere that the total volume of all gold mined since the beginning of civilization was something on the order of a cube a few hundred feet on a side. Current “motherlodes” are on the order of grams per ton. Finding one moderate sized asteroid with gold content measured in single digit percent would have interesting effects on the world economy - most specifically crashing the price of gold.

but you are right - the problem with modern tech is the range of goods needed. When simple items like light bulbs, toothpaste or shoes all need to be made locally or shipped at a cost of millions of dollars a ton and a lag time of months, a colony needs to be huge run all the industries to be self-sustaining; and until it is, a growing number of these mundane supplies and the industrial equipment need to be transported to a huge number of colonists. Motivations like “plant the flag” or “beat the Ruskies” only work for so long…

46

Yeah. One nit: If we quadrupled the world supply of gold, it would certainly cause the price to drop, but it would also open up vast new markets for gold, because gold is an incredibly useful material that we would like to use in many ways we cannot afford today. So while the price of bullion might drop, overall a massive source of gold (or platinum) would be a huge boon to the economy.

47

I wouldn’t say that gold is “incredibly useful”. It’s very dense, but we already have tungsten for that. It’s a good conductor, but copper is better. About all it really has uniquely going for it is its resistance to corrosion.

Oh, and there are a few other uses, like for shading the visors on astronauts’ helmets. But it was used for that because it’s already the cheapest metal around. I don’t think that making it even cheaper would make much difference.